Any one know the strength of 1" EMT (Conduit) ? Making homemade guard rails for Scaffolding

PhotowhitPhotowhit Posts: 4,660Solar Expert ✭✭✭✭
in Construction #1
Okay, I'm cheap, follow me long enough and you'll find me picking up broken tie downs from the side of the highway for the hooks! Or lugging home broken cedar fence, or dehydrating 3 bushels of apples while they're cheap (Now...lol)

So, I have a fear/respect for heights. I'm getting around to finishing some solar projects and I'm too cheap to buy Scaffolding Guard rail set up, particularly since I can only setup one long side for most of the jobs.

http://www.homedepot.com/p/MetalTech-7-ft-x-5-ft-Scaffold-Tower-Guard-Rail-System-M-MG507K/206733478

This appears to just be lighter than 1" conduit, (16 gauge 1" OD tubes) So I've purchased a single 1" conduit (Conduit is 1" inside) and drilled (I know this weakens it) for mounting in the scaffolding tubes and drilled some 5/16th inch holes for Snap Pins and drilled out holes in some 2x4's as cross members/rails, at @18 inches and 32-36inches, I eye balled it. It's job is just to keep me from stepping off the scaffolding. but I'm guessing it would support 100lbs.

I can post some pictures if anyone would like, it sounds a bit confusing, but I'm using the conduit is posts and 2x4's as rails, sitting on the snap pins which are about 3 inchs long.  There are no spec's as to what the guard rail will hold, but I'd guess there is some OSHA guild lines...
Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.

Comments

  • Dave AngeliniDave Angelini Posts: 3,880Solar Expert ✭✭✭✭
    #2
    The thickwall EMT I use 1.5", is very close to the snow load/wind spec of 1.5" water pipe which is generally specified for the ground mounts I use when I do not need tracking.
     I would not use the thin wall!  Hope this helps
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • softdownsoftdown Posts: 1,839Solar Expert ✭✭✭✭
    #3
    Iron plumbers pipe may be the strongest pipe for the dollar? Just guessing...

    I think grey PVC may be stronger, in some respects, than EMT.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • jonrjonr Posts: 1,025Solar Expert ✭✭✭✭
    #4
    My rough calculations suggest nowhere close to being stiff enough.  1.5" pipe looks minimally acceptable.
  • PhotowhitPhotowhit Posts: 4,660Solar Expert ✭✭✭✭
    #5
    1 1/2" steel pipe is what the scaffolding is made of... It won't fit within the pipe.

    I'm not trying to build scaffolding, I live near a nuke plant and have spoken to the fitters who build the massive multi story scaffolding from bare pipe and knuckles(?). I have scaffolding, just trying to figure out the strength of the guard rail I built.

    I do think regular galvanized steel pipe would be plenty strong even with the drilled holes, to be a heavy load bearing structure, I'm sure I could hang on it. The only thing available is black pipe which would not fair well living outside.

    It might surprise people that the braces for scaffolding have the same spec's as 3/4" conduit! ...but the max load is very minimal.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • softdownsoftdown Posts: 1,839Solar Expert ✭✭✭✭
    #6
    I've seen plumbers steel pipe, used in restaurants, to keep customers where they are supposed to be. With the tee's and accessories, you can easily build what you want. You may be able to slide thin wall pvc over it for weather-proofing...not sure.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Posts: 27,681Super Moderators admin
    #7
    Bracing may only be used in tension. And you can use cable and such too.

    Only need larger diameter/thick wall piping if used in applications to resist bending.

    If you put the railing under tension, then thin wall running/cable can be used.

    If the railing would collapse from side loading, then thick wall pipe would be better.

    -Bill "not a civil engineer" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdownsoftdown Posts: 1,839Solar Expert ✭✭✭✭
    #8
    Sometimes it is very hard to beat treated 2"x4"(s).
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • littleharbor2littleharbor2 Posts: 979Solar Expert ✭✭✭✭
    #9
    How about running a length of rebar inside the conduit?

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • BB.BB. Posts: 27,681Super Moderators admin
    #10
    Pipe would be stronger per unit weight if you are looking at bending resistance.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jonrjonr Posts: 1,025Solar Expert ✭✭✭✭
    #11
    > 1 1/2" steel pipe is what the scaffolding is made of... It won't fit within the pipe.

    So it might be possible to create a solid steel pin that connects the 1.5" scaffolding to a 1.5" post?  Or take what you have, set it a few feet above ground level and throw your weight at it.  I expect that how much a railing flexes is important to maintaining balance.
  • PhotowhitPhotowhit Posts: 4,660Solar Expert ✭✭✭✭
    #12
    I'm good, it works fine, when researching the strength, I found a welding site where a guy made scaffolding out of 16 gauge square steel made me for more comfortable. I'm done with the needs for guard rails. I'll reset up on the short side tomorrow and will post a picture.  I might make some out of heavier gauge steel pipe later.

    FWIW, I did think about inserting some 3/4" conduit inside to stiffen, but once I got my hands on the 1" I found it pretty strong/heavy (and lining up multiple holes would be a pain). I know the risk/weakest point is the holes drilled and tearing out. If I replace them I'll do a test. Mostly it's not intended to be load bearing, which I think the same goal as the company made hand rail. I do like having the 2x4 rail, set my drill on it several times.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • PhotowhitPhotowhit Posts: 4,660Solar Expert ✭✭✭✭
    #13
    Here are some photos of the guard rail, FWIW...

    It's on the low end of the array, so I really don't need them.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • mcgivormcgivor Posts: 2,037Solar Expert ✭✭✭✭
    #14
    You could always use sticks like they do in Laos.......just joking.  Have seen bamboo used in Hong Kong upwards of 30 stories, it's said they trust it over steel.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • softdownsoftdown Posts: 1,839Solar Expert ✭✭✭✭
    #15
    Bamboo is really strong. That would work fine for Photowhit.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • VicVic Posts: 2,907Solar Expert ✭✭✭✭
    #16
    The thickwall EMT I use 1.5", is very close to the snow load/wind spec of 1.5" water pipe which is generally specified for the ground mounts I use when I do not need tracking.
     I would not use the thin wall!  Hope this helps


    Am a bit late to this,   BUT,  EMT IS EMT,  IMC IS IMC,  and RGD (Rigid) pipe IS RGD.   EMT is not threaded,  IMC and RGD pipe IS threaded,  as supplied in 10' lengths:

    http://www.falsonsupply.com/Catalog/123FS.pdf

    FWIW,   Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • Dave AngeliniDave Angelini Posts: 3,880Solar Expert ✭✭✭✭
    edited November 2016 #17
    Definately but we can't always be as sharp as we want here. I did cover myself somewhat by saying the "thick wall" pipe is what you want for a mount. It is the same as schdule 40 water pipe which is often speced for ground mounting solar from my supplier Pro Solar.
    I think bamboo would really be hard to spec in a 50 service life...
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • PhotowhitPhotowhit Posts: 4,660Solar Expert ✭✭✭✭
    #18
    heck guy's the project's done and scaffolding down. My guess is that a 300lb guy falling 4 and a half feet against it would be retained on the scaffolding. I suspect I'll even replace it with heavier stuff, likely ridged pipe (RGD I've learned) and test the conduit for you at some later date.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • Dave AngeliniDave Angelini Posts: 3,880Solar Expert ✭✭✭✭
    #19
    Did you need any bamboo?
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • PhotowhitPhotowhit Posts: 4,660Solar Expert ✭✭✭✭
    #20
    No I managed without. Maybe when I'm home for Turkey day in Florida. Seriously it's great stuff and resilient. Likely a better choice than a 2x4 for rails...

    ...though setting a drill on it will take some talent!
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • mcgivormcgivor Posts: 2,037Solar Expert ✭✭✭✭
    #21
    Some pretty good videos on YouTube show how they build  bamboo  scaffolding, no drilling required.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

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